Self-burnishing contact point



Oct. 23, 1951 BRONSTElN 2,572,105

SELF-BURNISHING CONTACT POINT Filed Sept. 1, 1948 mum INVENTOR. ALBERT BRONSTElN A 7' TORNE X Patented o r. as, 1951 UNITED STATES PATENT OFFICE BELI-BUBNISHING CONTACT POINT Albert Bml'lltchl, Brooklyn, N. Y- Alpllcatlon September 1, 1m, Serial No. 67,220 2 Claims. (Cl. 3.0-3.)

This invention relates to self-burnishing electrical contactors.

The au omotive and aviation industries employ ele"tri a ignition e uipment in association with many of the motors used for propelling the automobile or the airplane. 'lhe i nition equipment thus employed, generally requires an electrical circuit breaker for purpo es of interrupting an e ectri al current. whi h in association with ad iti na e ectrical equi ment, su h as an autotransformer or spark coil, furnishes the ignition snark for the com ustion of a material within the cylinder of the motor.

Interruption of an electrical circuit containing a reactive com onent generally resu ts in the production of an electrical are between the contactors at whi-h the circuit is broken. Special precautions are necessary to minimize the effects of the electrical are which cau es burning and pitting of the contactors, and reduces the effective area of the contactors, generally requiring the early replacement of the contactors. According to one prior art practice, a condenser is used to reduce the burnin or pitting due to the arc, but this method is not entirely effective.

It is an object of my invention to form a circuit breaker assembly for ignition equipment wherein burning or pitting of the contactors is eliminated. In general, my invention includes two steps which cooperate to achieve this object. I have found that by rotating one of the contactors in a direction perpendicular to the contactor area during the period when the contactors are making and breaking an electrical circuit including a reactive component, pitting of the contactor is eliminated. Simultaneously, the contactors in operation contact one another when closing the circuit, causing a wiping between the contactors, and resulting in clean contactor surface areas.

In another aspect, I have applied my invention to a breaker system such as is commonly used in magnetos, and have further expanded the same principle to the contactors of electrical relays and the like.

Other objects and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawing and it will be apparent to those skilled in the art that many changes in the details of construction and arrangement of the parts described may-be made without departing from the spirit and scope of the invention as expressed in the accompanying claims. I therefore, do not wish to be limited to the exact de- 2 tails of construction and herein set forth, as preferred forms only have been given by way of illustration.

Referring to the drawing:

Figure 1 is a top view of an electrical ignition circuit breaker utilizing the invention.

Figure 2 is a sectional view along line 2-2 of Figure 1.

Figure 3 is a top view of an electrical magneto circuit breaker utilizing the invention.

Figure 4 is a sectional view along line 4-4 of Figure 3.

Figure 5 is a top view, partly in section, of an electrical relay including contactors utilizing the invention.

Referring in detail to Figures 1 and 2 of the drawing, an electrical ignition circuit breaker device I0, is formed with a base or support if, for supporting the circuit breaker contactor assemblies II and I8, and rotatable shafts l8 and 20. Shafts l8 and 20 have portions extending on both sides of support if, and are provided with afllxed gears 22 and 24 respectively. A further gear 28 is likewise affixed to shaft IO, all said gears being mounted on one side of support If, although they could likewise be mounted on the other side.

A'cam I0 is attached to shaft l8 and a worm gear 38 is attached to shaft 20. Cam I0 is emarrangement of parts ployed to make and break the circuit through the contactor assemblies.

Contactor assembly It comprises an arm 32 to which is secured contactor A and a fiber block or tooth 28. Ann 32 is further provided with a non-conductive bearing 34 thru which a shaft Na passes and secures the contactor assembly to support I2. A wire 35 is connected to arm I2. Contactor assembly I 8 comprises a bearing base assembly containing bearings 42 and 44, a

shaft 40 rotatably mounted and extending thru bearings 42 and 44, a gear 38 affixed to shaft II and between said bearings, and a contactor B aimed to shaft ll. The assembly is secured to support l2. v

The electrical ignition circuit breaker operates in the following manner. A driving torque, such as may be obtained from a gear shaft ll is applied to gear 26, rotating shaft ll, gear 22, and cam Ill. Rotation of gear 22 likewise causes rotation of shaft 20 and gear thru engagement of gear 24. Rotation of cam 30, on which tooth 28 rides under tension of a spring ll, causes he contactor surfaces to make and break completing and interrupting a circuit through contaetors A and B, said circuit completion and interruption being occasioned by the transverse motion-f contactor A. Contactor B is simultaneously rotated by means of gear 36 which engages gear 38 rotating the shaft 40 to which contactor B is affixed. In this manner, contact between the contactors is effected and broken during the p riod whence one contactor is rotated.

For another embodiment of my invention, reference is made to Figures 3 and 4 wherein similar numeral designations are employed for equivalent parts, wherever practical. The electrical magneto circuit breaker [0a, is formed with a base or support l2a for supporting the breaker contactor assemblies I la and 16a, and rotatable shafts iBa and 20a. Shafts Ma and 20a have portions extending on both sides of support I 2a, and are provided with amxed 'gears 22a and 24a respectively. A further gear 26:; is likewise attached to shaft Ilia.

A cam 30a is attached to shaft Mia, and a worm gear-36a is attached to shaft 20a.

Contactor assembly Ila comprises an arm 32a to which is secured contactor A and a block or tooth of insulating material 28a. Arm 32a is fastened to support Ma and insulated therefrom at point Z.

Contactor assembly l6a comprises a bearing assembly including bearings 42a and a, a shaft 40a rotatably mounted within said bearings 42a and 44a, and a contactor B.

Operation of the electrical magneto circuit breaker is similar to that of the electrical ignition circuit breaker. Although shafts l8 and 20. and 18a and 20a are shown geared to one an other through gears 22 and 24, and 22a and 2411, respectively, said gears could be replaced by separate driving means for the individual shafts.

My invention is also applicable to electromagnetic relays or switches, and I am including here in a description of an electromagnetic relay utilizing my invention.

Referring in detail to Figure 5, a relay comprising an electromagnetic 50 and a pair of contactors A" and B" in association with an armature 52 for opening and closing the switch formed by the contactors A" and B" and a rotating means for rotating contactor 13" form an embodiment of an electromagnetic relay employing my invention. In detail, the rotating means may comprise a gear 54, a shaft 56 and a bevel gear 58 coupled to a second bevel gear 60 connected to a shaft 62, to which is fastened contactor B". The rotating means is shown mounted in a casing 64.

In detail, the electromagnetic relay operates as follows; when coil or electromagnet 50 is energized from a source (not shown), armature 52, which is pivoted at point 65 is drawn to the electromagnet, bringing contactors A" and B" into contact. Contactor A" is tensioned against contator B" by means of a spring 68. Upon release of the energizing source, armature 52 is drawn away from the electromagnet by means of tensioning spring 68, simultaneously causing rack gear to engage gear 54, rotating contactor B".

It is to be noted that spring 66 releases the ten- 05 sioning force against contactor A" slowly, permitting rotation of contactor B" to commence before the contactor surfaces are disengaged.

Having thus disclosed several devices embodying my invention, I desire to reiteratethat the embodiments are for purposes of illustration, and I desire that the appended claims be interpreted in the light and scope of my invention.

What is claimed is:

1. An ignition system including a support; a first shaft rotatably mounted on said support; ignition current means including a circuit breaker; said circuit breaker including a first contactor and a second contactor; a polygonal shaped member affixed to said shaft and adapted to move said first contactor into and out of contact with said second contactor; a bearing assembly, said bearing assembly including a pair of bearings, a second shaft, having said second contactor secured at one extremity thereof, supported through said bearings and a gear secured to said shaft and between said bearings, a third shaft rotatably mounted on said support and parallel to said first shaft, a worm gear secured to one extremity of said third shaft and adapted to engage and rotate the gear secured to said second shaft, and gearing means between said first and third shafts adapted to rotate said second contactor as said first contactor is moved in and out of contact with said second contactor.

2. An ignition system including a support, a first shaft rotatably mounted through said support, a polygonal member secured to said first shaft, a circuit breaker comprising a first contactor assembly and a second contactor assembly, said first contactor assembly including a first contactor adapted to be moved laterally by said polygonal member, and said second contactor assembly including a bearing assembly, said bearing assembly including a pair of bearings, a second shaft adapted to ride said bearings, a gear secured to said second shaft and between'said bearings. and a second contactor secured to an extremity of said second shaft and adapted to come into and out of contact with said first contactor, a third shaft rotatably mounted through said support and parallel to said first shaft, a worm gear secured to one extremity of said third shaft and adapted to engage and rotate the gear secured to said second shaft, and gearing means of a predetermined ratio between said first and third shafts adapted to rotate said second contactor as said first contactor is moved in and out of contact with said second contactor.

ALBEl-tT BRONS'I'EIN.

REFERENCES orrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,064,122 Barrett June 10, 1913 1,413,905 Dean Apr. 25, 1922 1,690,538 House Nov. 6, 1928 2,127,957 Ives Apr. 23, 1938 2,387,961 Wihanto Oct. 30, 1945 

